It'll be interesting to see what happens there. They said that it would affect marginal, non-core routes and they have more frequency on that route than any other. The Aer Lingus code share might come into play as well.
I'd suggest the most threatened routes are the Ireland-UK routes with frequencies below daily (or daily excl Sat).
Those are
Donegal-Prestwick
Galway-Edinburgh
Sligo-Manchester
Kerry-Manchester (This might be particularly vulnerable with the Kerry PSO gone)
But those alone wouldn't justify dropping three aircraft. So there will probably be a few routes where they drop rotations as well.
I'm not sure what will happen with the Galway-Waterford-Amsterdam route. I doubt it's profitable at the moment, so whether they continue to try to grow it might depend on how much of a cash problem they have.